text: Police verified that on the morning of May 13, the boys and girls of 3B class were playing and biting each other's hands?
classes:  No, police have been involved in a case involving two students biting each other while joking at school.  Also, police have been involved in a case involving two students biting each other while joking at school.  Yes, police have been involved in a case involving two students biting each other while joking at school.